基于量子干涉的阿秒电子波包测量方法研究

Electron is the most elementary particles constructing the matter world. The electron behavior affects the internal ultrafast processes in atoms and molecules. Measuring the ultrafast evolution of electron wave packet with high time resolution is important not only for the understanding of the process of microscopic electronic ultrafast dynamics, but also for the study of the ultrafast dynamics in many other subjects such as basic physics, chemistry, material science and life science. To date, the method used for the detection of attosecond electron wave packet as well as the measuring instrument, such as VMI and COLTRIMS, can only measure the amplitude, while cannot extract the phase. Since the phase of electron wave packet contains the important information of the wave property of the electron, the absence of the phase information has greatly restricted the further in-depth understanding of the physical nature of the ultrafast electron behavior. In this projection, we propose to develop a method that can measure both amplitude and phase of the attosecond electron wave packet at the same time. Analogous to the SPIDER diagnostic method for laser pulses, a momentum shear between the electron wave packets is formed, and then the amplitude and phase can be obtained simultaneously from the quantum interference fringe. By optimizing and controlling the evolution of the electron wave packet, the visibility of interference fringes can be significantly improve, which leads to a more accurate measurement.

电子作为构成物质的最基本粒子，电子的行为影响着原子、分子内部的超快动力学过程。对电子波包的高时间分辨超快测量不仅为认识微观电子超快运动过程带来重要的研究手段，而且在基础物理学、化学、材料和生命科学等学科的超快动力学研究中有重要应用前景。目前国际上所采用的阿秒电子波包测量方法以及发展起来的相应测量装置如VMI、COLTRIMS等只能测得其振幅，却不能同时测量反映电子波动性重要信息的电子波包相位，从而制约了人们对于电子超快行为物理本质的进一步深入认识。本项目拟开展可以同时获得阿秒电子波包振幅和相位完全信息的测量方法研究。类比SPIDER诊断激光脉冲的方法，通过在阿秒电子波包之间形成一个动量剪切量，获得量子干涉条纹，并从干涉条纹中同时提取阿秒电子波包的振幅和相位信息。通过对电子波包演化过程的控制与优化，提高测得的干涉条纹可见度，进一步提升测量准确度。

电子作为构成物质最基本的粒子，其行为影响原子、分子内部超快动力学过程。对电子波包实现阿秒时间分辨率和埃空间分辨率的超高精度测量对认识微观世界最本质物理过程和物理规律具有重要意义。我们针对基于光电子干涉的电子波包测量方法开展了研究，阐明了光电子干涉获取物理学信息的理论原理，以此为基础，发展了光电子全息成像法，用以提取物理学信息。在研究中，我们建立了同时获得电子波包振幅和相位的完全信息的测量方法，用此方法成对分子中超快电子迁移过程实现了阿秒时间量级和埃空间量级的追踪；准确获得了电子波包强场电离时间。此外，我们还建成了离子电子成像研究实验平台；以及探测了超快核运动过程，向电子波包-核关联动力学过程探测进行发展延伸。在本项目的资助下，我们发表了学术论文16篇，其中包括Physical Review Letters 3篇，Nature Communication 1篇。